Sub/Sat Speaker Systems
The subwoofer/satellite speaker system has been around for
a long time -- the first time I heard a good setup was in the early 1980s -- but today
they’re far more popular than ever. In fact, right now such systems are a staple of
the computer industry -- many personal computers are sold with two tiny speakers,
nicknamed satellites (sats for short), one for each side of your screen,
plus a small subwoofer (sub), for placement on your desktop or the floor. However,
these computer speaker systems often sound poor and are cheaply made, and don’t
indicate what a high-quality sub/sat system can provide.
Luckily, you can find better. In fact, in the world of
high-quality two-channel audio -- the equipment we review here at GoodSound! -- a
high-performance, three-piece sub/sat speaker system, properly set up, can outperform a
like-priced two-speaker setup . . . if you know what you’re
doing.
In a typical three-piece sub/sat system, the small
satellite speakers take care of the upper-bass, midrange, and high frequencies -- things
small speakers are best suited for. The single subwoofer handles the bass -- something
that small speakers are not good for, though a properly designed subwoofer, even a
small one, is. The first question you might have is, Why just one sub and not two?
After all, you need two speakers for stereo.
The wavelengths of bass frequencies are so long that they
end up being omnidirectional -- that is, they seem to come from all directions at once.
Therefore, when those frequencies are reproduced, our ears have difficulty locating the
source. As a result, bass frequencies are inherently monaural: you don’t need two
sources to create a stereo effect -- deep bass will sound just as spacious from a single
source as from two. On the other hand, the far shorter wavelengths of the upper-bass, mid,
and high frequencies are much easier to locate by ear; for those, you do need two
speakers to create the stereo effect of re-creating a sense of three-dimensional aural
space.
One advantage of sub/sat systems is their small size, which
increases the number of places they can be placed in the room. For example, smaller
satellite speakers can be placed on bookshelves or stands -- or attached to the wall,
which is what I’ve done with a pair of sats in my family room. And because deep-bass
frequencies aren’t directional, you don’t have to place the sub between or even
near the satellite speakers -- you can stash it off to the side, in a corner, or even
behind the listening position. Large floorstanding speakers that would normally be placed
in imposing positions in the front of the room simply don’t give you these kinds of
options. No wonder people like sub/sat systems.
However, the sub/sat approach is about more than just
convenience. It’s quite possible to achieve superior performance with such a speaker
system -- this is because, for midrange and high-frequency clarity as well as soundstaging
and imaging, the best speaker positions in the room are often not the best
positions for low-bass response. So, with an all-in-one speaker system, you try to make do
with speaker positions that make the best compromise between the two. But with a sub/sat
system, you can optimize the positions of the sats so that the midrange, highs,
soundstaging, and imaging are spot on, then place the sub wherever in the room it produces
the best bass. You don’t have to compromise at all. (To help you do this, Philip
Beaudette has written a feature article, "How to Set Up Your Subwoofer -- Placement
Basics.")
However, that doesn’t mean that everyone should sell
their regular stereo speakers and run out and get a sub/sat speaker system. Such systems
have their downsides, and one of these has to do with getting it set up right. For
example, although this type of speaker setup lets you optimize the placements of sats and
sub, it also means that you have to know what you’re doing to get the speakers in
just the right positions, and then to tweak the setup to get a blend cohesive enough that
the entire system sounds "as one." To do that, you often have to tweak the
placement of the sub, and fiddle with its level, crossover-frequency, and phase controls
(either on the sub itself or with the controls of your A/V receiver, if you have one).
Sometimes, it’s not that easy and you end up with a disjointed sound that’s
inferior to what you’d get from a regular stereo pair of speakers.
Another potential problem is knowing exactly how to hook up
the three speakers; there’s more than one way to do it. Furthermore, how you hook
them up will depend on your associated electronics and on the sub itself -- there’s
no cookie-cutter solution, and not all components have the same connection options. The
most common way to hook up a subwoofer is to use its line-level input (most of
today’s subs have one), but you can do this only if your receiver or preamplifier has
a line-level sub output.
But that’s not the only way to hook up a sub. You can
also drive it in high-level fashion by hooking it up to the amplifier with speaker cable,
just as you would a regular speaker. However, you then must decide at which frequency the
sub will "cross over" to the satellites to achieve the proper blend. You are, in
a way, playing speaker designer, and the result will have a tremendous impact on whether
or not the system sounds cohesive. For instance, it’s possible to run the satellites
"full range," meaning that they’ll produce some of the deeper bass
frequencies along with the sub. It’s also possible to use a crossover to cut off the
bass frequencies going to the satellites and the high frequencies going to the sub. Most
subs have such a crossover built in; alternatively, you can use an external crossover.
What’s important to remember is that there’s not just one way.
While sub/sat systems can be a little tricky to set up,
don’t be too wary of them -- they can offer tremendous convenience. More
important, if you get yours set up right, then, in my opinion, you can achieve better
performance than with a like-priced two-piece speaker system.
If this type of system interests you, check out our reviews
this month -- of the SVS SBS-01 loudspeaker and PB10-NSD subwoofer, and the NHT Classic
Two loudspeaker and Classic Ten subwoofer. As you’ll see, both systems offer good
value and good performance -- which is exactly what GoodSound! is all about.
…Doug Schneider
E-mail comments to the editor@goodsound.com.
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